The triangular array formed from the coefficients of sin + cos is discussed in relation to Pascal's triangle. (JG)

Using the secant ratio rather than the cosine in trigonometric calculations is discussed. (DT)

A mathematical misteak" is an incorrect operation that leads to a correct result. An introduction to the use of the misteak" to emphasize the mathematical operations being taught. Examples and brief explanations of several types of misteaks" are given. (FL)

The graph of this function is analyzed by using calculus methods and the computer. The graph in most texts is shown to be misleading. (MP)

Complex numbers and trigonometry are used to prove that a given constructed line is equal to the length of one side of a regular pentagon inscribed in a unit circle. (MP)

Methods are presented for teaching the meaning of exponential functions, Euler's formula, De Moivre's theorem and Maclaurin's series for exponentials, cosine, and sine to juniors or seniors in high school. (JG)

This article demonstrates an iterative method of evaluating the cosine function which can be derived using secondary school trigonometry. A sample computer run is included. (MM)